Go 1.16 adds support of 64-bit ARM architecture on macOS (also known as Apple Silicon) with GOOS=darwin, GOARCH=arm64. Like the darwin/amd64 port, the darwin/arm64 port supports cgo, internal and external linking, c-archive, c-shared, and pie build modes, and the race detector.
The iOS port, which was previously darwin/arm64, has been renamed to ios/arm64. GOOS=ios implies the darwin build tag, just as GOOS=android implies the linux build tag. This change should be transparent to anyone using gomobile to build iOS apps.
Go 1.16 adds an ios/amd64 port, which targets the iOS simulator running on AMD64-based macOS. Previously this was unofficially supported through darwin/amd64 with the ios build tag set.
Go 1.16 is the last release that will run on macOS 10.12 Sierra. Go 1.17 will require macOS 10.13 High Sierra or later.